1. Field of the Invention
The present invention generally relates to a knee brace. More particularly, the present invention relates to a knee brace for enhancing quadriceps muscle contraction during knee extension for centering the patella and thus enhancing patellar function.
2. Description of the Prior Art
As noted in U.S. Pat. No. 6,540,708 ('708 patent), the physiological motion of the human knee involves complex dynamic motion. Prior art knee bracing apparatuses and systems have attempted to control or otherwise manage the complex motions associated with knee extension, knee flexion, as well as polycentric motion more fully articulated in the '708 patent. Notably, the patella is typically stabilized by the insertion of the vastus medialis and the prominence of the anterior femoral condyles, which normally prevent lateral dislocation of the patella during flexion. Lateral dislocations do occur, however, given knee injury and other abnormal knee developments. Certain prior art patent discloses describing certain apparatuses and means for externally or superficially managing various forms of joint articulation, and particularly knee joint articulation, are briefly set forth hereinafter.
U.S. Pat. No. 4,370,977 ('977 patent), which issued to Mauldin et al., discloses a Knee and Elbow Brace. The '977 patent teaches an improved knee brace comprising thigh and calf cuffs and identical side members to simplify manufacture and permit use with a range of leg sizes. The hinge members on each of the side members permit the knee joint to be immobilized at a predetermined degree of flexion or movable within a predetermined arc of motion such as 0-degree to 30-degree flexion or 30-degree to 60-degree flexion. A tensioned cord is provided to urge the knee joint in a given direction. The spring force may be employed to inhibit the quadriceps muscles or permit progressive resistance exercises during rehabilitation. In a first modification, a torsion spring replaces the tension cord and forms the preferred embodiment. In a second modification, a torsion spring is also employed with a thumb screw which permits the knee joint to be immobilized at any desired degree of flexion. In a second embodiment, an elbow brace is provided for supporting and rehabilitation of the elbow joint and adjacent body portions in the arm. A hinge member permits pivotal motion of the elbow brace about an axis corresponding to the axis of the elbow joint. A spring provides a moment about the pivotal axis of the hinge member to inhibit the biceps muscle and provide a variable resistance to motion to rehabilitate the elbow joint and surrounding tissues.
Similarly, U.S. Pat. No. 4,433,679 ('679 patent), which issued to Mauldin et al., discloses a Knee and Elbow Brace. The '679 patent teaches a knee brace comprising a first hinge portion having a face comprising a plurality of circumferentially equally spaced teeth. An adjusting disc has a first circular face comprising teeth which mesh with the teeth of the first hinge portion to lock the component parts of the knee brace in any desired angular relationship. A second hinge portion has a face comprising a plurality of slots. The adjusting disc has a second circular face comprising a tooth which is selectively engageable with one of the slots of the second hinge portion to regulate angular movement between the component parts of the knee brace. A torsion spring has projections which are selectively positionable in apertures of the first and second hinge portions to apply a predetermined torque to the component parts of the knee brace.
U.S. Pat. No. 4,624,246 ('246 patent), which issued to Ajemian, discloses a Knee-Supporting Brace. The '246 patent teaches a knee-supporting brace comprising a pair of structures to be adapted to be fastened to a leg from both sides of the knee. Each structure includes two elongated solid members rotatably connected to each other which are adapted to be fastened respectively above and below the knee. Two springs connect these elongated members respectively between their upper ends and their lower ends so that the user must exert a force to stretch the springs but the compressed springs aid the user when the knee is straightened as the user stands up.
U.S. Pat. No. 4,665,905 ('905 patent) which issued to Brown, discloses a Dynamic Elbow and Knee Extension Brace. The '905 patent teaches a wire frame structure of two parallel aligned members formed into a compression spring centrally positioned to provide controlled force at each end. U-shaped yokes are adjustably affixed to the aligned members, one to each end. The yokes are hinged to cuffs suitable for attachment to human arm or leg members by self-fastening straps and adjacent the center springs, two additional securing straps are provided. In use, the brace assemblage provides a dynamic tension to apply a controlled force on an elbow or knee flexion contracture.
U.S. Pat. No. 4,817,588 ('588 patent), which issued to Bledsoe, discloses a Motion Restraining Knee Brace. The '588 patent teaches a motion restraining knee brace having a pair of articulated side portions each defined by elongated thigh and calf support members pivotally interconnected by an adjustable hinge mechanism. Each hinge mechanism has a single adjustment dial that cooperates with a pair of stop members to selectively limit the relative pivotal movement between the thigh and calf support members associated with the hinge. Outer ends of the thigh and calf support members are securable to the leg by connecting straps which encircle the leg and have independently adjustable anterior and posterior portions. Each of the thigh and calf support members is formed from two adjustably interlockable longitudinal sections releasably held together by a pivotable clip member to thereby provide for rapid support member length adjustment. To inhibit extension of the leg beyond the hinge established extension limit angle of the brace, a restraining strap member is looped through eyed connectors carried by each of the support members to form a generally hourglass-shaped strap network positioned behind the knee. As the leg is extended, the strap network is progressively tightened against it, with each portion of the network being held in essentially equal tension, to inhibit overextension of the leg.
U.S. Pat. No. 4,838,251 ('251 patent), which issued to Chignon et al., discloses a Dynamic Knee Brace. The '251 patent teaches a knee brace comprising a thigh-piece and a legging capable of pivoting between an extended position and a bent position, together with springs stretched over the sides of the brace between anchor elements fixed to the thigh-piece and the legging in order to urge the thigh-piece and the legging to pivot relative to each other towards at least one of said positions without impeding the movement thereof.
U.S. Pat. No. 4,865,024 ('024 patent), which issued to Hensley et al., discloses an Extension Deceleration Orthosis. The '024 patent teaches an extension deceleration orthotic fulcrum for knee and elbow braces, which simulates performance of the function of those ligaments that control joint motion and provide anteroposterior joint stability, comprising a lightweight, external spring assembly, upper and lower elongated arms, and centric or polycentric fulcrum, which is adjustable for its range of motion, adaptable for use on many different style orthoses, and whose strength can be varied to suit corrective, preventive, anthropomorphic, environmental, and usage requirements, including means both for mechanically dampening the limb's angular velocity on extension to prevent hyperextension and for accelerating the limb's angular velocity on flexion to enable quicker, smoother, less stressful motion. In one embodiment spring rods are assembled medially and laterally to conventional pairs of elongated orthotic brace arms to span the joint fulcrum point by serpentinely engaging novel roller posts, the assemblage thus serving to decelerate the limb during the last 15 to 20 degrees of extension, to help prevent the striking of a stop with its attendant risk of hyperextension, and thus serving to use the stored energy of the spring to facilitate flexion of the limb.
U.S. Pat. No. 4,938,206 ('206 patent), which issued to Harris et al., discloses a Floating Pivot Hinge and Knee Brace. The '206 patent teaches a knee brace comprising a thigh cuff having inner and outer spaced brace arms adapted to extend along the user's thigh toward the knee, a calf cuff including inner and outer spaced brace arms adapted to extend along the user's calf toward the knee, and floating pivot axis hinges rotatably connecting the inner and outer brace arms of each pair. The hinge is formed by a pair of juxtaposed hinge plates, each having a pivot face in opposition to a pivot face on the juxtaposed plate, with a concave groove in each of the face. A pivot bearing ball is confined between the opposed faces and retained in the concave grooves. A spring, bellville spring, or disk spring biases the hinge plates together when the pivot bearing ball is positioned in the opposed grooves between. The pivot bearing ball provides a floating pivot axis for hinge rotation of said hinge plates and thereby said braces relative to each other, the ball and concave grooves allowing the hinge plates simultaneously to slide and pivot relative to each other. The pivot axis floats between the hinge plates depending on the degree of pivoting and sliding movement in a wearer's knee joint as a result of flexion thereof.
U.S. Pat. No. 4,961,416 ('416 patent), which issued to Moore et al., discloses a Knee Brace. The '416 patent teaches a leg brace usable after knee ligament surgery utilizing first and second members which are held to the femoral and tibial portions of the leg. A hinge mechanism is also included in the brace for permitting pivotal rotation between the first and second members with the bending or flexion of the knee. A bar is extended across a selected portion of the leg. The bar is biased against the leg by a spring to prevent translation between the tibia and femoral for a particular angular range of extension of the knee portion of the leg.
U.S. Pat. No. 5,352,190 ('190 patent), which issued to Fischer et al., discloses a Knee Brace. The '190 Patent teaches an apparatus for use in bracing or exercising a knee joint in a manner that allows bending of the joint only along a predetermined path which approximates the natural bending of the joint. On one side of the joint are upper and lower struts that run along and are attached to the upper and lower leg and are attached to one another near the joint by a connecting mechanism which includes a set of linkage arms and telescoping elements that allow the struts to pivot relative to one another along the prescribed pivot line. On the other side of the joint are other upper and lower struts that run along and are attached to the upper and lower leg and are attached to one another near the joint by a ball and socket connector. The apparatus may be used as a brace or, alternatively, may be used with a cycling mechanism to cyclically flex and extend the joint or with a force-applying mechanism to apply a constant force urging the extension or flexing of the joint.
U.S. Pat. No. 6,074,355 ('355 patent), which issued to Bartlett, discloses a Knee Brace. The '355 patent teaches a testing device for determining the amount of tension in the quadriceps muscle for the anterior cruciate ligament to fail. There is also provided a knee brace having three point fixation and includes a pair of first arm members positioned on opposite sides of the knee joint. The lower leg brace member has a pair of second arm members oriented and positionable on opposite sides of the knee joint. The rigid thigh member and lower leg member are secured to the wearer's leg by means of a flexible strap extending around the back of the leg and adjustably attached thereto. The mating ends of the arms are connected by a pair of parallel spaced-apart face plates forming polycentric hinges which permit the mating ends of the arms to pivot about the connections. Various forms of extension cushions are provided to limit the proximity of the mating ends to one another to thereby limit the forward movement of the arms.
U.S. Pat. No. 6,413,232 ('232 patent), which issued to Townsend et al., discloses an Orthopedic Knee Brace having an Adjustable Knee Pad Support. The '232 patent teaches an orthopedic knee brace has a pair of femoral and tibial links, a hinge mechanism connecting the femoral and tibial links, a condylar knee pad support fixedly positioned on the lateral side of the brace and made adjustable by a spring-loaded ratchet mechanism featuring a series of interlocking teeth that allows for the axial displacement of the condylar pad to supply corrective force to the lateral knee joint and prevent of any unintended change in correction force. Moreover, in an effort to provide greater flexibility to the wearer in and enhance the stabilization of the design, the condylar pad is mounted for rotation about a point on the axis of the femoral condyle of the knee joint. The knee pad support may be adjusted by hand by rotating the ratchet mechanism to achieve the proper correction force or with an adjusting tool that engages a plurality of notches surrounding the periphery of the ratchet mechanism.
U.S. Pat. No. 6,540,708 ('708 patent), which issued to Manspeizer, discloses a Polycentric Joint for Internal and External Knee Brace. The '708 patent teaches an internal or external knee brace having a polycentric joint that enables control of a predetermined helicoidal motion and which permits compression and distraction of the knee joint. The knee brace includes a femoral component having a femoral joint member having at least one mating surface with a predetermined contour, and a stem projecting from the femoral joint member for attachment to the femur. The knee brace further includes a tibial component having a tibial joint member having at least one bearing surface for contact with the mating surface of the femoral component, and a stem projecting from the tibial joint member for attachment to the tibia. The joint members are arranged in a mounting member which has a spring or other resilient member located at one end which biases the tibial component toward the femoral component. The femoral component is fixed in the mounting member and the tibial component is rotatable relative to the fixed femoral component.
It will be seen from a further review of the above-referenced patents and other prior art generally known to exist relating to knee-bracing systems that the prior art perceives a need for a knee brace that functions to extensionally center and thereby enhance patellar function comprising an upper bracket assembly, a lower bracket assembly, and a pair of torsional spring assemblies, which torsional spring assemblies comprise elastically compressible core elements. By providing a torsional spring element with an elastically compressed core element, the actuation of a torsional spring element may be effectively damped for reducing stress on the treated joint.